Based on field outcrop data, the effects of cyclic change of astronomical orbit and volcanic activity on organic carbon accumulation during the Late Ordovician – Early Silurian in the Upper Yangtze area were studied using cyclostratigraphic and geochemical methods. δ¹³C and chemical index of alteration (CIA) were used to filter the astronomical orbit parameters recorded in sediments. It is found that the climate change driven by orbital cycle controls the fluctuations of sea level at different scales, obliquity forcing climate changes drive thermohaline circulation (THC) of the ocean, and THC-induced bottom currents transport nutrient-laden water from high latitude regions to the surface water of low-latitude area. Hence, THC is the main dynamic mechanism of organic-carbon supply. The marine productivity indexes of Ba/Al and Ni/Al indicate that volcanic activities had limited effect on marine productivity but had great influences on organic carbon preservation efficiency in late Hirnantian (E4). Paleo-ocean redox environmental indicators Th/U, V/Cr and V/(V+Ni) show that there is a significant correlation between volcanism and oxygen content in Paleo-ocean, so it is inferred that volcanisms controlled the organic carbon preservation efficiency by regulating oxygen content in Paleo-ocean, and the difference in volcanism intensity in different areas is an important factor for the differential preservation efficiency of organic carbon. The organic carbon input driven by orbital cycle and the preservation efficiency affected by volcanisms worked together to control the enrichment of organic carbon in the Middle–Upper Yangtze region.

以野外露头资料为基础，利用旋回地层学和地球化学方法，研究了天文轨道循环变化和火山活动对上扬子地区晚奥陶世—早志留世有机碳积累的影响。δ ¹³ C 和化学变化指数 ( CIA)) 用于过滤沉积物中记录的天文轨道参数。发现轨道周期驱动的气候变化控制不同尺度海平面的波动，倾斜强迫气候变化驱动海洋温盐环流（THC），THC诱导的底流从高纬度地区输送富含营养的水到低纬度地区的地表水。因此，THC 是有机碳供给的主要动力机制。Ba/Al和Ni/Al的海洋生产力指数表明火山活动对海洋生产力的影响有限，但对海南阶晚期（E4）的有机碳保存效率有很大影响。古海洋氧化还原环境指标 Th/U, V/Cr和V/(V+Ni)表明古海洋火山活动与氧含量之间存在显着相关性，推测火山活动通过调节古海洋氧含量来控制有机碳保存效率，不同地区火山活动强度的差异是有机碳保存效率差异的重要因素。轨道循环驱动的有机碳输入和火山活动影响的保存效率共同控制了中上扬子地区有机碳的富集。不同地区火山活动强度的差异是有机碳保存效率差异的重要因素。轨道循环驱动的有机碳输入和火山活动影响的保存效率共同控制了中上扬子地区有机碳的富集。不同地区火山活动强度的差异是有机碳保存效率差异的重要因素。轨道循环驱动的有机碳输入和火山活动影响的保存效率共同控制了中上扬子地区有机碳的富集。